This is a GM decision, but as written the lance does double, triple when spirited, damage, not the character. To show the difference you can see the “Order of the Claymore” which gives the Cavalier double damage on a charge. The RAW of the Lance says the ” A lance deals double damage when used from the back of a charging mount. While mounted, you can wield a lance with one hand.” So 2d8 + all other bonuses instead of 1d8 + all other bonuses.